Most fevers resolve on their own within one to three days, and recovery comes down to supporting your body while it fights off the underlying infection. A fever is not the illness itself. It’s your immune system raising your internal thermostat to create a hostile environment for viruses and bacteria. Your job during recovery is straightforward: stay hydrated, rest, manage discomfort, and know when a fever signals something more serious.
What’s Happening Inside Your Body
When your immune system detects an infection, it signals your brain to raise its temperature set point. Your normal baseline hovers around 98.6°F (37°C), but during a fever it can climb to 100.4°F (38°C) or higher. This is why you feel cold and shivery at the start of a fever: your body is trying to generate heat to reach that new, higher target. You might pile on blankets, curl up, and feel genuinely chilled even though your temperature is rising.
As your body gains ground against the infection, the set point drops back to normal. But your actual temperature is still elevated, so now you feel hot. That’s when your sweat glands kick in, producing sweat to cool you down. If you’re suddenly drenched in sweat, it often means the fever is breaking and you’re turning a corner. This sweating phase is a natural cooling mechanism, not something you need to force by bundling up or exercising.
Fever also increases your metabolic rate by roughly 11% for every degree Celsius above normal. That means your body burns through calories and fluids faster than usual, which is why you feel so drained even when you’re just lying in bed.
Staying Hydrated Is the Priority
Fluid loss accelerates during a fever. Your body loses water through sweat, faster breathing, and the increased metabolic demand. For every degree Celsius above 38°C (100.4°F), fluid losses through the skin increase by about 10%. That adds up quickly, especially if your fever runs high for more than a day.
Water is the foundation, but you’re also losing electrolytes through sweat. Oral rehydration solutions, diluted sports drinks, or broth can help replace sodium and potassium. Sip frequently rather than gulping large amounts at once, especially if nausea is part of the picture. Signs you’re falling behind on fluids include dark yellow urine, dry mouth, dizziness when standing, and producing very little urine. Children and older adults dehydrate faster and may need more deliberate encouragement to keep drinking.
Eating When You Don’t Feel Like It
Your appetite will likely drop, and that’s normal. But because your metabolic rate climbs significantly during a fever, your body needs fuel even if you don’t feel hungry. You don’t need to force full meals. Small, frequent portions of easy-to-digest food work better: toast, rice, bananas, scrambled eggs, soup, or oatmeal. Protein matters for immune function, so try to include some even in small amounts.
If eating feels impossible, prioritize calorie-containing fluids like smoothies, milk, or broth with noodles. Going a day with minimal food won’t cause harm in most adults, but if a fever stretches beyond two or three days, making an effort to eat becomes more important.
Managing Discomfort With Medication
Fever reducers won’t make the infection go away faster, but they can make you feel significantly better while your body does its work. The two main options for adults are acetaminophen (Tylenol) and ibuprofen (Advil, Motrin). Both lower temperature and relieve the body aches that come with fever.
You can alternate these two medications if one alone isn’t providing enough relief. Take one first, then wait four to six hours before taking the other. You can continue alternating every three to four hours throughout the day. For adults, stay under 4,000 milligrams of acetaminophen and 1,200 milligrams of ibuprofen in a 24-hour period. If you find yourself alternating consistently for more than three days, that’s a signal to check in with a healthcare provider.
For children under 12, the same alternating approach can work, but dosing is based on body weight. A pediatrician can give you the right numbers. One firm rule: never give aspirin to children or teenagers with a fever. Aspirin has been linked to Reye’s syndrome, a rare but serious condition that can develop after viral infections like the flu or chickenpox.
Keep Your Environment Comfortable
Your instinct might be to pile on heavy blankets or, alternatively, to take an ice-cold shower. Neither helps. Bundling up traps heat and can push your temperature higher. Cold water or ice baths trigger shivering, which actually generates more internal heat and works against you. Research on tepid sponge baths in children found they caused more discomfort (crying, shivering, goosebumps) without producing a meaningful temperature difference after two hours compared to doing nothing.
Instead, keep the room comfortably cool without making it cold. Wear lightweight, breathable clothing. A single light blanket is fine if you feel chilly. If you want to use a compress, make it lukewarm rather than cold. The goal is to let your body release heat gradually without triggering a shivering response that fights the cooling process.
Rest and Sleep
This sounds obvious, but it’s the part people most often shortchange. Your immune system does some of its heaviest lifting during sleep, and the elevated metabolic demand of a fever means your body is already working harder than normal. Pushing through a workday or trying to exercise while febrile slows recovery and increases the risk of complications like dehydration.
Give yourself permission to sleep as much as your body wants. Most adults find that the first 24 to 48 hours are the worst, with energy gradually returning as the fever breaks. Don’t rush back to full activity the day your temperature normalizes. A day or two of lighter activity after the fever clears helps your body finish recovering.
Fever in Infants and Young Children
The rules change for babies. Any fever in an infant younger than 3 months warrants an immediate call to a healthcare provider, regardless of how the baby seems otherwise. For babies 3 to 6 months old, call if the temperature reaches 100.4°F (38°C) or higher, or if the baby seems unusually fussy, lethargic, or unwell even at lower temperatures. For children 6 to 24 months, a fever above 100.4°F that lasts more than one day needs medical attention. For any child, a fever lasting more than three days should be evaluated.
Young children can dehydrate quickly, so frequent small sips of fluid (or breast milk or formula for infants) are essential. Watch for fewer wet diapers, no tears when crying, or a sunken soft spot on the head as signs of dehydration.
Warning Signs That Need Immediate Attention
Most fevers are caused by common viral infections and resolve without incident. But certain symptoms alongside a fever point to something more urgent. Seek immediate care if a fever comes with any of the following:
- Stiff neck with pain when bending the head forward
- Severe headache or unusual sensitivity to bright light
- Confusion, altered speech, or strange behavior
- Rash, especially one that doesn’t fade when pressed
- Persistent vomiting that prevents you from keeping fluids down
- Difficulty breathing or chest pain
- Abdominal pain or pain when urinating
- Seizures
In adults, a fever above 103°F (39.4°C) that doesn’t respond to medication, or any fever lasting more than three days, is worth a call to your doctor. The combination of a stiff neck, severe headache, and light sensitivity is a classic pattern for meningitis, which requires emergency treatment.